Brown called for the resignation of US Attorney General Eric Holder and blasted Warren as a “jobs destroyer” during an appearance from 8-9 p.m. on WBZ-AM radio with conservative host Dan Rea, a longtime friend of the Brown family.

Warren had declined an invitation to debate Brown on Rea’s show after Brown rejected a debate proposed by Victoria Reggie Kennedy, widow of the late Senator Edward M. Kennedy, a Democrat. But shortly after Brown left the airwaves, Warren appeared on MSNBC as a guest of left-leaning political talk show host Rachel Maddow, accusing Brown of playing political games over the Holder issue.

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Rolling her eyes, Warren said of Brown, “I think this is when people get disgusted by politics.”

The candidates have significant financial incentive this week to appeal to their most fervent supporters, with the fund-raising quarter set to close on Saturday. Both campaigns are eager to finish the period with strong numbers — to claim bragging rights and boost their war chests in what is expected to be one of the most expensive Senate races in the country.

In response to a question during his interview, Brown said that Holder had lost the confidence of Congress and could not effectively serve President Obama due to a controversial federal gun sting in Mexico, in which some guns allowed to go over the boarder reportedly have been used in crimes.

Later in the show, he asserted that the Harvard professor would make the problem of illegal immigration worse, and told a small business owner who called in to the program that Warren wanted to raise her taxes.

“She wants to raise your taxes and take more money out of your pocketbooks and wallets,” he said.

Addressing other questions, Brown declined to recommend a vice presidential choice for Mitt Romney, would not offer up a guess as to whether the Supreme Court will overturn the president’s health care law, and praised the economic development efforts of Boston Mayor Thomas M. Menino.

Warren, on Maddow’s show, offered a sustained attack on Brown’s call for Holder’s resignation, before quickly transitioning into her stump speech on jobs, college education, and “accountability on Wall Street.”

“There’s really serious stuff on the table and that’s what we should be talking about,” she said.

Asked about the Bay State’s most urgent problems, Warren cited home foreclosures and homeowners underwater with their mortgages.

“Massachusetts is recovering better than much of the rest of the country, partly because we have made a lot of investments in our people,” she said

The candidates have significant financial incentive this week to appeal to their most fervent supporters, with the fund-raising quarter set to close on Saturday.

The state’s US Senate race has been billed as the most compelling this year. Both candidates are prolific fund-raisers with national standing. Four months before the vote, opinion polls suggest a deadlocked race, and partisan control of the US Senate could hang in the balance.

But each candidate has suffered self-inflicted distractions of late: Voters tuning in recently might assume the race is between a challenger who has failed to provide proof that she’s Native American and an incumbent who brags about secret royal meetings that didn’t happen.

Warren’s campaign stumbled for several weeks earlier this year after disclosures that the Harvard professor and consumer advocate identified herself as Native American in statistics reported to the federal government by her employers. Warren maintains that the claim of Native American ancestry, based on family lore, did not help her career.

Brown attacked her on those assertions Wednesday night, saying Warren failed the “honesty, credibility, and trustworthiness test,” and repeated his call for her to release all of her college employment records.

In an interview after his appearance Brown declined to say if he thought Warren had gotten a career boost by claiming Native American status, and repeated his call for her to release records as “the only way” to know for sure.

Warren did not address the Native American controversy on Maddow’s show.

Brown last week raised eyebrows by saying in a radio interview that as a senator he works daily on issues in “secret meetings with kings and queens.”

He later backtracked, through a spokesman, saying he “misspoke” and had not really rubbed elbows with royalty. The Democratic Party swiftly followed up by revealing video footage of Brown repeatedly making the “kings and queens” boast since 2010.

Brown addressed the controversy during the broadcast Wednesday, saying that he made a mistake and stepped on his larger point, which was that officials around the world are talking about a crisis in jobs.

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